This invention relates to a method for culturing a microorganism having a tolerance to an organic solvent. In further detail, this invention relates to a method for culturing a microorganism having a tolerance to an organic solvent selected from among hydrocarbons, alcohols, ethers, ketones, their derivatives and their mixtures.
As conventional examples of culturing a microorganism in a medium containing hydrocarbons or their derivatives, there are such many reports as of the growing of Nocardia sp. in a medium containing hexane or hexadecane [R. L. Raymond, Appl.. Microbiol., vol. 15, pp. 857.about.865 (1967)], the growing of Bacterium JOB5 in a medium containing cyclopentane or cyclohexane [J. Ooyama and J. W. Foster, Antonie von Leenwenlook, vol. 31, pp. 45.about.65 (965)], the growing of Fseudomonas sp., Achromobacter sp., and Nocardia sp. in a medium containing benzene, ethyl benzene, toluene or xylene [D. Cleus and N. Walkes, J. Gen. Microbiol, vol. 36, pp. 107.about.122 (1964)], etc. can be enumerated. However, these microorganisms are cultured by bringing the same into contact with hydrocarbons which are concentrated low or in the form of steam in any case owing to the fact that hydrocarbons generally show toxicity to microorganisms. That is, when the fermentation is carried out by using these hydrocarbons as substrates, it is carried out by supplying these compounds in the form of steam so that the compounds are not brought into contact with microorganisms directly or by maintaining these compounds in low concentration (0.2or less) at which a toxic effect is not shown. Consequently, in the fermentation using hydrocarbons as substrates, there are problems not only of low productivity but also of operation because of the difficulty in controlling the substrates to low concentration. Furthermore, in case of using a lightly water-soluble substance, there is a disadvantage that the productivitY becomes low in &he microbial reaction going to the low solubility of the substance.